Earlier this year, when the British Film Institute’s monthly magazine Sight & Sound announced the results of its most recent “greatest films of all time” poll — a once-every-decade exercise that Roger Ebert has called the only poll taken seriously by anyone who works in the film business — cinephiles were astounded to learn that Citizen Kane had been toppled from its perennial perch atop the list. The greatest film of all time, according to hundreds of critics, festival programmers and others around the world was not Orson Welles’ 1941 drama, but Alfred Hitchcock’s 1958 masterpiece of unease and obsession, Vertigo.

While the rest of BFI’s 2012 list is comprised of standard film-geek fare — Renoir’s Rules of the Game, John Fords’ The Searchers and so on — the excellence and legitimacy of the winners is hardly up for debate. They’re all powerful exemplars of the art of cinema.

But what about the greatest movie of all time? What about the best, most thoroughly enjoyable, most enduringly, rightfully beloved movie ever made? A film, after all, is generally understood to be a creation that aspires to the status of art; a work of import, depth and vision brought to the screen almost solely through the passion and drive of its director — its auteur.

A movie, on the other hand, is an unabashedly pop-culture creation whose purpose is to entertain — and, of course, make money. While the director, screenwriter, producer, cast and crew working on a movie might very well strive for real quality, most everyone involved knows and accepts that if it doesn’t put people in the seats, it can hardly be judged a success.

With that distinction in mind, now is as fine a time as any to celebrate the best movie ever made: Casablanca. Monday, Nov. 27, is the 70th anniversary of the New York City premiere of Michael Curtiz’s 1942 marvel, and in the years since it first beguiled moviegoers, no other moving picture has surpassed its inspired mix of writing, acting, atmosphere, romance, intrigue and, finally, its absolutely sublime pacing — elements so neatly intermeshed that they’ve kept the Bogart-Bergman wonder running like a beautiful, finely tuned Cadillac for seven decades.

It’s hardly original, of course, to tout Casablanca as a classic. After all, it won Oscars for Best Picture, Best Director and Best Adapted Screenplay against some pretty stiff competition (Watch on the Rhine, Madame Curie, The Ox-Bow Incident, et al.). On sheer numbers alone, it’s a very, very good movie.

But what sets Casablanca apart not only from so many terrific movies made in the early ’40s but, ultimately, from every other American movie, period, is what might be termed its accidental perfection.

The most immediately obvious example of the movie’s uncanny good fortune is its impeccable cast. That most of the principal roles were filled by Warner Bros. regulars (Bogart as the mercenary with a romantic streak, Rick Blaine; Sydney Greenstreet as the cheerfully amoral Signor Ferrari; Peter Lorre as Ugarte; Claude Rains as slippery, corrupt Captain Renault; Dooley Wilson as Rick’s piano-playing pal, Sam; and on and on) is not merely a strong argument for Hollywood’s often-pilloried “studio system” of the ’20s through the ’60s. The fact of the matter is all of those roles — as well as minor characters, like Leon Belasco’s dealer in the casino at Rick’s Cafe, or Joy Page’s Bulgarian newlywed who considers offering herself to Renault in exchange for passage to America, and freedom, for both her clueless husband and herself — has something to say, and through the inspired craft of the actors, every role says it with ease and professional, off-handed grace.

Ingrid Bergman, meanwhile, who plays the absurdly beautiful Ilsa Lund, brought a European sensibility to her part that feels sensual, rather than merely sexy. The way she plays off — or against — the often rougher-edged Warner regulars generates a heat that makes it achingly obvious why Bogart’s Rick is crazy for her.

And then there’s the writing. Based on an unproduced play by Murray Burnett and Joan Alison, the Casablanca script by twin brothers Julius and Philip Epstein, Howard Koch and the great Casey Robinson (uncredited) is a master-class of dialog, tone — somehow world-weary and earnest at once — and deftly handled mid-World War II propaganda that actually works as propaganda.

Beyond the countless memorable single lines in the movie (Here’s looking at you, kid … Round up the usual suspects … Of all the gin joints in all the towns in all the world, she walks into mine … We’ll always have Paris …), the script features scene after scene filled with dialog that any actor would relish the chance to utter:

Renault: What in heaven’s name brought you to Casablanca?Rick: My health. I came to Casablanca for the waters.

Renault: The waters? What waters? We’re in the desert.Rick: I was misinformed.

Finally, there’s Michael Curtiz’s sure, seemingly effortless direction, and the superb pacing of the movie’s 102 minutes. The Budapest-born Curtiz was no slouch at any time — in the space of a few years in the late ’30s and early ’40s he helmed several of the most popular entertainments Hollywood has ever seen, from The Adventures of Robin Hood to Yankee Doodle Dandy — but with Casablanca he managed something that feels an awful lot like magic. The movie, after all, is hardly a straightforward adventure, romance or WWII picture. There are flashbacks, clandestine meetings, heroic gestures, musical interludes (including a singing of “La Marseillaise” that, after all these years, can still bring tears to the eyes of pretty much anyone who has a heart), betrayals, reunions, Nazis, shootings and more than a few bits of outright comedy.

Yet, with all of that swirling around the central, eternal story of Rick and Ilsa’s war-torn romance, the movie still has an utterly coherent, propulsive vibe. One can watch the movie once and get it. One can watch it a dozen times and revel, every time, in the way that Curtiz ties the enormous themes — war, sacrifice, courage, love — and the smaller moments together in a way that feels both companionable and new.

That it all ends on what is, arguably, the most famous closing line in movie history (“Louis, I think this is the beginning of a beautiful friendship.”) doesn’t just feel apt. After having spent an hour-and-a-half watching the best movie ever made, the completeness of the final scene feels, somehow, inevitable.

Let’s be clear: no one in his or her right mind would argue that a film, as described above, cannot be entertaining, while a movie is purely and simply a popcorn-and-profit venture. Citizen Kane, for instance, has moments as light and engaging as anything in, say, Crazy, Stupid, Love, while a movie as preposterous (and wonderful) as the futuristic sci-fi dragon parable Reign of Fire offers glimpses of battlefield grandeur that might not be out of place in a Kurosawa epic.

Generally speaking, though, the line between film and movie, while perhaps not always terribly broad, is nevertheless quite bright. On the 70th anniversary of its premiere, it’s only right that we celebrate the most treasured title on the latter side of that line. Like Rick and Ilsa and their adored Paris, we’ll always have Casablanca. And really, what movie lover could ask for more?